In modular furniture construction, such as the type of furniture used in laboratories and offices, cabinet structures (drawer units, door-equipped units, and shelf units) are often suspended from the worktops or their supporting rails. Where such units are screwed or bolted to the supporting structure, attachment is awkward and sometimes quite difficult because the connecting elements are not always readily accessible.and the cabinet units are often heavy and difficult to support while the connecting points are being located and the screws or other connectors are being inserted and tightened. Also, the provision of fixed connecting points prevents or at least greatly limits the extent of adjustment in the position of a cabinet unit after the connectors have been inserted and before they are fully tightened.
Ideally, means should be provided for suspending a cabinet structure so that it may be moved laterally along the width of the worktop and, when the desired position is selected, the mounting means may then be easily tightened to draw the cabinet against the undersurface of the worktop in such a way that all gaps or seams between the parts are tightly closed and the facing surfaces of the parts are disposed in flush relation. While various types of mounting systems have been proposed to permit lateral adjustment of cabinet units, and while clamps of different construction have been disclosed in the prior art, the systems used in the past typically have fallen short of meeting all of these objectives either because of complexity, inconvenience of operation, or inability to achieve both adjustability and security of attachment. Reference may be had to U.S. Pat. Nos. 3,266,762, 3,185,418, 3,333,799, and 3,445,081 for various types of suspension clamps disclosed in the prior art.
In my copending application, Ser. No. 870,889, filed June 5, 1986, I disclose a generally J-shaped clamp with an upstanding stem portion, an upper arm portion, and a hook-shaped lower arm portion. The upper arm portion terminates in a rib that projects towards the lower arm portion and also includes a threaded bore which extends along a line that is generally parallel with the lower arm portion and is spaced above the rib. A screw is threadedly received within the bore and, during use of the clamp, the upper arm portion is hooked over the flange of a support rail and the screw is tightened against the rail to pivot the clamp and to force the top wall of a cabinet unit, supported by the clamp's lower arm portion, upwardly into tight engagement with the rail.
The clamp of the copending application therefore allows a user to shift a loosely suspended cabinet into the desired location beneath the supporting rail of a worktop and then to tighten the clamp with a wrench or other suitable tool, causing the clamp to pivot and draw the cabinet unit upwardly into tight engagement with the rail structure. Two or more such clamps may be used depending on the width of the suspended cabinet unit. Detachment of the cabinet structure is easily accomplished simply by reversing the procedure.
While the clamp of the copending application overcomes most of the shortcomings of the prior art, one disadvantage has now been noted, namely, that while such a clamp in partially-tightened condition effectively suspends the front portion of a cabinet in a way that permits lateral and forward-rearward adjustment in the position of that cabinet, there is a possibility that a user may, in making such an adjustment, draw the cabinet forwardly (towards the user) to such an extent that the cabinet's rear flange or lip could become disengaged from the support beam of the worktop or wall structure. Thus, as shown in FIG. 3 of that application, if the cabinet unit 14 were drawn forwardly (to the left) a sufficient distance, lip 19 would release from beam 20. While in such a case the front of the cabinet 14 would still be supported by the clamp or clamps 30, a twisting or torquing action might nevertheless occur and result in damage to the cabinet unit. In any event, the disengagement of the lip from the support rail would require the installer to repeat some of the installation steps and to exercise care that the same over-adjustment does not occur again.
An important aspect of this invention therefore lies in providing a clamp which is simple in construction and operation, which allows a user to shift a loosely-suspended cabinet into the desired location beneath the supporting rail of a worktop and then to tighten the clamp with a wrench or other suitable tool, causing the clamp to pivot and draw the cabinet unit upwardly into tight engagement with the rail structure, and which allows the user to adjust the position of the cabinet structure prior to tightening of the clamp without the risk that such adjustment might result in the unintentional release of the rear portion (or any other portion) of the suspended cabinet unit.
Briefly, the clamp is composed of three pieces: an upper jaw member, a lower jaw member, and a screw that adjustably connects the two jaw members together. The upper jaw member includes a horizontally-extending body having a depending bearing portion at one end and a depending clamping rib at the opposite end thereof. The lower jaw member similarly includes a horizontally-extending body having an upstanding bearing portion at one end and an upwardly-projecting clamping rib at the opposite end thereof. In addition, the lower jaw member is provided with an intermediate retention rib. The adjustment screw extends vertically, when the clamp is in use, having its head disposed beneath the lower jaw member with its threaded shank extending upwardly through an enlarged opening in that jaw member. The threaded upper end of the screw is threadedly received in an opening provided by the upper jaw member. Because the opening in the lower jaw member is substantially larger than the shank of the screw, the two jaw members may not only be moved away from each other when the screw is loosened but may also be angularly displaced with respect to each other. The jaws may therefore be spread apart when the elements are loosely pre-assembled to permit the clamp to be fitted in place. Partial tightening of the screw assures that the clamp will not become released and, further, that forward-rearward adjustment of the cabinet will be limited by the retention rib of the clamp, and by the adjustment screw, to preclude unintended release of the cabinet from its suspended condition. With the clamp in partially tightened condition, the cabinet is free to be slid laterally into its desired position of adjustment, at which time the clamp is tightened to secure the cabinet in the selected position.
Other features, objects, and advantages will become apparent from the specification and drawings.